Luminescent tube



Patented Apr. 11, 1933 v UNITED STATES PATENT OFFICE GEORGES CLAUDE, OFBOULOGNE SUR SEINE, FRANCE, ASSIGNOR TO CLAUDE NEON LIGHTS, INC., 01 NEWYORK, N. Y., A CORPORATION OF NEW YORK LUMINESCENT TUBE No Drawing.Application filed June 8, 1929, Serial No. 369,534, and in France August30, 1928.

This invention relates to gaseous conductor tube lights of the kind inwhich a column of more or less rarefied gas is rendered luminous by thepassage of current between 5 spaced electrodes.

two or more kinds of atoms. Almost invariably the operating conditionswhich are realized tend to favor the Vibration of one kind of atom anddampen the vibrations of the other kind. One of the most strikingexamples of this phenomena arises when a IIllX- ture of neon gas andmercury vapor in a tube having capillary portions is subjected to acurrent. The spectrum of mercury is attained in the portions of greaterdiameter, while in the narrower portions only the spectrum of neon isvisible. Similarly, the v1- bration of nitrogen or hydrogen atoms 1n atube of constant diameter containing a mixture of neon with only a fewthousandths parts of nitrogen or hydrogen masks the neon spectrum.

The object of the present invention is a luminous tube containing aplurality of gases and wherein the vibration of the atoms of the gaseouscontents are not dampened but light from all the gases blend to producea light of pleasing appearance. More particularly, a mixture of heliumand neon in a positive column tube light is utilized to produce a verygood correction of the wan helium light. For example, if neon is addedto the helium in a discharge tube in the proportions, say of one-onehundredth or even one-one thousandth part of neon to one part of helium,when the gaseous contents are ionized, the spectrum of neon appears in avery steady manner and in such a way that the resulting light is neitherthe light emitted by helium nor that of neon but both blend to produce avery pretty pinkish color which is the more accentuated as theproportion of neon increases. Even when the neon is present in the tubein an amount as small as one-one thousandth part to one part of helium,the correction of the helium light is noticeable.

The luminous eificiency of such a luminous tube, i. e., the amount oflight emitted per watt input, is improved over that of a discharge tubecontaining only helium, doubtless because the proportion of the totalradiation furnished by the neon is attended with the excellentefiilciency inherent in this gas for luminescence. The luminousefiiciency of the tube is also a function of the pressure of gas. in thetube and hence, as the pressure is increased, the intensity of thepinkish color increases, that is, if the pressure of the gaseouscontents is increased a lower percentage of neon will give the sameluminous efliciency as a higher percentage of neon in a tube wherein thetotal pressure of the gaseous contents is less. For instance, with amlxture of 0.5% of neon and 99.5% of helium in a r tube of 33millimeters diameter and in which the barometric pressure is 1millimeters of mercury, the color of light emitted is of a pale pinkcolor whereas the color is caused to be decidedly darker if thebarometric pressure is increased to 3 millimeters of mercury.

It is thus seen that the quality of the light emitted by a gaseousconductor tube and its efliciency is increased by adding to the heliumcontents a quantity of neon and it has been found that the percentage ofneon may vary from less than one one-thousandth part to from 3 to 5% ormore and even to 15% according to the effect to be obtained, thediameter of the tube, and the pressure.

Various modifications will occur to those skilled in the art in thegaseous components of the tube and their proportion and the totalpressure as well as the character of tube electrodes and no limitationis intended by the phraseology of the foregoing description except asindicated in the appended claims.

What I claim is 1. A luminous tube containing one or more of the raregases including neon, wherein the percentage of neon ranges from 0.001to 0.15.

' 2. A luminous tube containing neon and a rare gas wherein theproportion of neon is from less than 0.1 per cent to 15'per cent.

3. luminous tube containing noon and helium wherein the proportion ofneon is from 0.1 per cent to 15 per cent.

4. A luminous tube containing neon and helium in the proportion of 0.5per cent neon to 99.5 per cent helium.

5. A luminous tube containing neon and I helium in the ratio of fromless than 0.1 per cent of neon to 3 per cent thereof.

6. The method of obtaining a blended neon-helium light in which thespectra of both gases are blended which comprises blending neon withhelium in the ratio of not over 15 per cent neon and discharging anelectric current through the mixture.

In testimony whereof I aflix my si nature.

GEORGES GLA E.

